Porous membranes, materials, composites, laminates, textiles and related methods

ABSTRACT

The present invention is directed to novel, improved, modified or treated microporous membranes for use in textile related applications and which are preferably composed of two or more dissimilar porous membrane or material layers laminated together using heat, compression and/or adhesives. The preferred inventive laminated composite microporous membrane is modified using a technique or treatment such as microcreping to introduce permanent small, regularly spaced, crepes, profiles, compactions, pleats, or wrinkles into the laminated composite microporous membrane for the purpose of improving mechanical strength, elasticity and/or resiliency. In addition, the inventive microcreped microporous laminated membrane more preferably has significantly improved ‘hand’ or softness, has ‘next-to-the-skin’ softness, and/or is quiet without crinkling noises during movement, which may be desired performance properties or characteristics of or in textile garments, materials or applications.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application based on U.S. patentapplication Ser. No. 14/037,845 filed Sep. 26, 2013, now U.S. Pat. No.______, which claims the benefit of and priority to U.S. provisionalpatent application Ser. No. 61/706,990 filed Sep. 28, 2012, bothincorporated by reference herein.

FIELD OF THE INVENTION

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, modified, or treated porous membranes,materials, composites, laminates, textiles, garments, textile materials,and related methods. In accordance with at least certain embodiments,the present invention is directed to novel, improved, modified, ortreated microporous membranes for use in textile garments, textilematerials or related applications. In accordance with at least certainselected embodiments, the present invention is directed to novel,modified or treated composite microporous membranes which are composedof two or more dissimilar porous membrane or material layers laminatedtogether, for example, using heat, compression and/or adhesives. Inaccordance with at least particular selected embodiments, the laminatedcomposite microporous membrane is modified using a technique ortreatment such as microcreping to introduce permanent small, regularlyspaced, crepes, profiles, compactions, pleats, or wrinkles into thelaminated composite microporous membrane for the purpose of changing,modifying or improving certain characteristics or performance such asmechanical strength, elasticity and resiliency. In addition, theinventive novel, improved, modified, treated, or microcreped microporouslaminated membrane may have significantly improved ‘hand’ or softnesswhich is a desired characteristic or performance property in textilegarments, materials or applications.

BACKGROUND OF THE INVENTION

Microporous membranes are commonly made of polyolefins and are used innumerous end use applications such as medical and industrial filtration,battery separator membranes, separation methods, deaeration, water andfluid purification, etc. Such membranes are available from Celgard, LLCof Charlotte, N.C. Due to their chemical nature, polyolefin microporousmembranes are hydrophobic and repel water. While water in the liquidstate is repelled by polyolefin porous membranes, water vapor moleculesin their gaseous state are able to permeate into the porous structure ofthe membrane and pass through its pores.

Microporous membranes that are water impermeable and air permeable couldbe useful as materials for waterproof/breathable textile materials andapparel including footwear, as well as in certain industrialapplications, such as building construction, where a combination ofwaterproofness and breathability may be desirable. Such membranes areavailable from Celgard, LLC of Charlotte, N.C.

A need exists for such membranes for at least certain uses orapplications to not only have waterproofness and breathability, but alsoto have increased mechanical strength to withstand the rigors ofrepeated use, a degree of stretch and recovery to enhance wearer comfortor to improve the membrane's conformability to twists and bends, and/orto have improved ‘hand’ or drape.

SUMMARY OF THE INVENTION

At least selected embodiments, objects or aspects of the presentinvention address the above needs and/or are directed to novel,improved, modified, or treated porous membranes having in addition towaterproofness and breathability, greatly enhanced usefulness and scopeof application, increased mechanical strength to withstand the rigors ofrepeated use, a degree of stretch and recovery to enhance wearer comfortor to improve conformability to twists and bends, and/or improved ‘hand’or drape.

In accordance with at least selected embodiments, the present inventionis directed to novel, improved, modified, or treated porous membranes,materials, composites, laminates, textiles, garments, textile materials,and related methods. In accordance with at least certain embodiments,the present invention is directed to novel, improved, modified, ortreated microporous membranes for use in textile garments, textilematerials or related applications. In accordance with at least certainselected embodiments, the present invention is directed to novel,modified or treated composite microporous membranes which are composedof two or more dissimilar porous membrane or material layers laminatedtogether, for example, using heat, compression and/or adhesives. Inaccordance with at least particular selected embodiments, the laminatedcomposite microporous membrane is modified using a technique ortreatment such as microcreping to introduce permanent small, regularlyspaced, crepes, profiles, compactions, pleats, or wrinkles into thelaminated composite microporous membrane for the purpose of changing,modifying or improving certain characteristics or performance such asmechanical strength, elasticity and resiliency. In addition, theinventive novel, improved, modified, treated, or microcreped microporouslaminated membrane may have significantly improved ‘hand’ or softnesswhich is a desired characteristic or performance property in textilegarments, materials or applications.

In accordance with at least selected embodiments, objects or aspects,the present invention is directed to novel, improved, modified, ortreated microporous membranes for use in textile garments, textilematerials or related applications, to novel, modified or treatedcomposite microporous membranes which are composed of two or moredissimilar porous membrane or material layers laminated together, forexample, using heat, compression and/or adhesives, to laminatedcomposite microporous membranes modified using a technique or treatmentsuch as microcreping to introduce small, regularly spaced, crepes,profiles, compactions, pleats, or wrinkles into the laminated compositemicroporous membrane for the purpose of changing, modifying or improvingcertain characteristics or performance such as mechanical strength,elasticity and resiliency, to treated or microcreped microporouslaminated membranes having significantly improved ‘hand’ or softnesswhich is a desired characteristic or performance property in textilegarments, materials or applications, and/or the like.

The possibly preferred inventive laminated composite microporousmembrane is modified using a technique or treatment such as microcrepingwhich introduces preferably permanent, small, regularly spaced, crepes,profiles, compactions, pleats, or wrinkles into the membrane. Thecreping, pleating or folding of the microporous membrane produces a 3-Ddimensionality to the architecture or profile of the membrane whichpreferably results in a marked increase in mechanical strength and inthe level of stretch and recovery. In addition, treating or microcrepingthe laminated composite microporous membrane preferably creates a soft‘hand’ or drape in the microporous membrane which is in contrast to thetypical ‘plastic’; rigid feel of certain polyolefin membranes. Unlikethe stiff feel of an inexpensive plastic raincoat, the inventivemicroporous membrane preferably has ‘next-to-the-skin’ softness and isquiet without crinkling noises during movement.

Microcreping involves the introduction of permanent, tiny crepes orprofiles into at least a portion of the structure of the porous membraneor film in a process which compresses the web or length of material toproduce the crepes or profiles. This process may also be known ascompaction. FIG. 1 shows an example of a textile fabric which has beenmicrocreped, creating rows of microcreped areas which generated rows ofgathering or wrinkles in adjacent areas of the fabric. Depending on thecreping pattern, the microcreped material may appear to have stripedareas of small crepes and larger gatherings or wrinkles laid out in arepeated parallel fashion.

While microcreping is known in the art (see, for example, U.S. Pat. Nos.3,260,778, 5,666,703, and 5,678,288, and US Published Application US2008/0036135 A1, each hereby incorporated by reference herein), theconcept of microcreping the inventive microporous membranes, microporouscomposites or laminates, and microporous polymer membranes laminated toa non-woven material for use as a textile material is a differentiated,novel or improved concept and/or product for textile garments, materialsand/or applications, and/or other end use applications.

One method of creping webs, commonly referred to as “microcreping,” isdescribed in U.S. Pat. No. 3,260,778 issued Jul. 12, 1966 to Richard R.Walton and entitled “Treatment of Materials” (and incorporated byreference herein). This U.S. Pat. No. 3,260,778 patent describes amethod in which the web is supported on the surface of a rotating drumand lengthwise compressed in a treatment cavity defined by the surfacesof the rotating drum, a primary blade which presses the web against therotating drum, and an inclined rigid retarder blade which retards theforward movement of the web and dislodges the web from the surface ofthe rotating drum. The treatment cavity prevents the web from bucklingbeyond the dimensions of the treatment cavity, causing a lengthwise ormachine direction compression of the web which results in creping.

The microcreping of the present laminated composite microporous membraneintroduces a three dimensional architecture into the structure of themembrane preferably resulting in a markedly increased level ofmechanical strength and elasticity. Furthermore, the inventivemicrocreped microporous membranes have significantly improved ‘hand’ orsoftness depending on the degree of creping or compactness obtained inthe microcreping process.

Polyolefin microporous membranes (such as Celgard® polyolefinmicroporous membranes of Celgard, LLC of Charlotte, N.C.) are typicallywaterproof due to the inherent hydrophobic nature of the carbon-hydrogenpolymeric material they are composed of and the small pore size. Whilewater in the liquid state is repelled by polyolefin microporousmembranes, water vapor is able to permeate the microporous structure andpass through the pores of the membrane. The porous structure of amicroporous membrane allows for the permeation and passage of moleculesin their gaseous state through the membrane. Passage of gaseoussubstances in and out of the microporous membrane defines the airpermeability and moisture vapor transmission performance of themembrane.

In accordance with at least selected embodiments, the present inventionis related to microcreping composite microporous membranes whichpreferably include a first microporous polymer membrane laminated to asecond porous membrane or material which is preferably a non-woven, morepreferably a polymer non-woven, but can be one or more other polymericporous membranes, or to a porous membrane previously coated with amaterial, such as a polymeric functional material, selected forstrength, porosity and surface friction properties. A critical componentof the success of microcreping a microporous polymer membrane, such as aCelgard® microporous polyolefin membrane which has been laminated to aporous polymer non-woven material or mesh, such as a polyolefinnon-woven mesh, more specifically of a Celgard® Z-series (i.e. biaxiallyoriented) microporous polyolefin membrane product laminated to a porouspolyolefin non-woven material, can be due in part to the difference inthe friction properties of the two porous membranes or materials (forexample, the polymer membrane and polymer non-woven each have differentfriction properties), to the unevenness, grip or friction properties ofthe non-woven material (for example, the polymer non-woven), or thelike. FIG. 3 shows side by side photographs of a Z-series Celgardmembrane EZL2090 before and after microcreping. Because the laminationprocedure involves heat, the lamination diamond pattern in the EZL2090creates distinct porous and nonporous area in the membrane. Althoughthis diamond lamination pattern may be preferred, the present inventionis not limited to any particular lamination pattern or creping pattern.

In addition to microcreping, fabric softness can be enhanced through,for example: material selection; embossing such as to create a pillowingeffect; selecting lamination techniques, such as adhesive and/orlow-temperature lamination, that maximize softness; subjecting thelaminate (or at least the outer surface or layer) to mechanicalworking/beating; laminating softer materials on one or both outersurfaces; and/or treating the laminate (or at least the outer surface orlayer) with fabric softening finishes.

The resulting inventive microcreped microporous membrane producedthrough the microcreping process may offer a range of differentiatedtextile materials with waterproof/breathable performance properties.

The resulting inventive microcreped or softened novel, improved,modified, or treated porous membranes, materials, composites, laminates,textiles, garments, textile materials, microporous membranes, materials,composites, laminates, textiles, garments, textile materials, compositemicroporous membranes which are composed of two or more dissimilarporous membrane or material layers, laminated composite microporousmembranes, and/or the like may offer a range of differentiatedmaterials, textile materials or the like, preferably withwaterproof/breathable performance properties.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a photographic image at 10× magnification of a fabric whichhas been microcreped. The flat portion is where the microcreping hastaken place resulting in gathering of the remaining material. Photo fromMicrex Corporation website www.micrex.com.

FIG. 2 is a schematic representation of the surface appearance ofmicrocreped Celgard® Z-Series Microporous Membrane.

FIG. 3 includes side by side photographic images of samples of Celgard®Z-Series Composite Microporous Membrane and Microcreped Celgard®Z-Series Composite Microporous Membrane showing the before (on the left)and after (on the right) microcreping in accordance with one embodimentof the invention.

FIG. 4 is a photograph of Example 2 EZL3030 Microcreped CompositeMicroporous Membrane.

FIG. 5 is a series of photographs (1-3) showing the drape/softness/handof the Nonwoven Membrane (1), Microporous Base Membrane (2) and theInventive Microcreped Microporous Membrane (3).

DETAILED DESCRIPTION OF THE INVENTION

In accordance with at least certain possibly preferred embodiments, thepresent invention is directed to novel, modified or treated microporousmembranes for use in textile related and other applications. Inaccordance with selected possibly preferred embodiments, the presentinvention is directed to novel, modified or treated compositemicroporous membranes composed of two or more dissimilar porous membraneor material layers laminated together using heat, compression,ultrasonic bonding and/or adhesives. In accordance with at least certainpossibly preferred particular embodiments, a laminated compositemicroporous membrane composed of two or more dissimilar porous membraneor material layers laminated together is modified using a technique ortreatment such as microcreping to introduce preferably permanent small,regularly spaced, crepes, profiles, compactions, pleats or wrinkles intothe laminated composite microporous membrane for the purpose ofimproving mechanical strength, elasticity and/or resiliency. Inaddition, the inventive modified, treated or microcreped laminatedcomposite microporous membrane has significantly improved ‘hand’ orsoftness, ‘next-to-the-skin’ softness, and/or is quiet or withoutcrinkling noises during movement, each of which is a desired performanceproperty in textile garments, materials or applications.

As one example, Micrex Corporation of Walpole, Mass. is the developer ofa series of machine configurations known as Micrex®/Microcrepers™ whichimpart microcrepes of various patterns on traveling material lengths orwebs.

The creping or microcreping of the laminated composite microporousmembrane introduces a three dimensional architecture into the structureof the membrane preferably resulting in a markedly increased level ofmechanical strength and elasticity. Furthermore, the inventivemicrocreped microporous membrane can have significantly improved ‘hand’or softness depending on the degree of creping or microcreping orcompactness obtained in the creping or microcreping process.

Polyolefin microporous membranes are waterproof due to the inherenthydrophobic nature of the carbon-hydrogen polymeric material they arecomposed of and the small pore size. While water in the liquid state isrepelled by polyolefin microporous membranes, water vapor is able topermeate the porous structure and pass through the micropores of themembrane. The porous structure of a microporous membrane allows for thepermeation and passage of molecules in their gaseous state through themembrane. Passage of gaseous substances in and out of the porousmembrane defines the air permeability and moisture vapor transmissionperformance of the membrane.

In accordance with at least selected embodiments, the present inventionis related to microcreping laminated composite microporous membraneswhich include a first polymer microporous membrane which has beenlaminated, bonded, joined, or adhered to a second porous membrane ormaterial which is preferably a non-woven fabric, but can be one or moreother polymeric porous membranes or a porous membrane previously coatedwith a polymeric functional material selected for strength, porosity andsurface friction properties, or a woven or knit porous fabric.

A possibly critical component of the success of microcreping porousmembranes, such as Celgard® porous membranes which have been laminatedto a non-woven layer, material or fabric, more specifically of aCelgard® Z-series PO, PP, PE, or PP/PE/PP microporous membrane productlaminated to a Polyolefin (PO) non-woven material, can be due in part tothe difference in the friction properties of the respective outersurfaces of the porous membrane and non-woven fabric, the frictionproperties of the outer surface of the non-woven fabric, or the like. Inaccordance with at least one embodiment, the inventive membrane can alsobe laminated to a woven fabric comprised of nylon, PET, PP, cotton,rayon, acrylic, or other material or combination of materials. Inaccordance with at least one embodiment, the inventive membrane can alsobe laminated between two layers of non-woven, between a layer ofnon-woven and a layer of woven fabric, or between two layers of wovenfabric and bonded together thermally, ultrasonically, or with adhesive.In accordance with at least one embodiment, the inventive microcrepedcomposite microporous membrane can consist of a single layer microporousmembrane which has one surface modified to alter its frictionalproperties as needed for successful microcreping.

The resulting inventive microcreped microporous membrane producedthrough compaction or microcreping offers a range of differentiatedtextile materials with waterproof/breathable performance properties.Examples of possible industrial textile related end uses of theinventive microcreped microporous membrane include flexible packaging,sound insulation, construction barrier films, cushioning applications,and increased surface area film for filtration and/or gas diffusionapplications. Examples of possible textile related garment applicationsinclude disposable and/or reusable medical garments, clean room suits,outdoor textile materials, outdoor clothing or gear, footwear, etc.

The resulting levels of strength, stretch, recovery, stretch andrecovery, resiliency, flexibility, and softness may be controlled byvarying the degree of creping or compaction, for example, compaction ormicrocreping of at least a portion of the membrane in the machinedirection. Adjustment of compaction or creping parameters such as speed,pressure and temperature, may regulate the achieved level of mechanicalstrength, stretch and recovery, resiliency, and soft hand of themicrocreped porous membrane. Higher compaction may produce a more dense,microcreped material with higher resiliency, that is, recoverablemachine direction stretch. The soft hand or softness of the microcrepedmembrane, the ability of the creped material to hang or droop, and thelike is created by the parallel rows of microcreped areas or lands andthe adjacent gathers in the membrane shown in, for example, FIGS. 2 and3. The drape and softness of the inventive microcreped microporousmembrane (3) is shown in FIG. 5 as compared to the component non-woven(1) and base porous membranes (2). This example demonstrates that twosoft, easily draped membranes can be microcreped to produce theinventive microporous membrane where the drape and softness are retainedor even improved.

Microcreping of Celgard® polyolefin microporous membranes, morespecifically to Celgard® Z-series microporous membrane productslaminated to a non-woven material, provides a highly breathable,waterproof, resilient material useful for garment applications such asouterwear, rainwear, waterproof footwear, hunting and motorcycle gear,surgical garments, etc. and also useful for textile outdoor applicationswhich use tenting and awning materials, etc.

EXAMPLES

The below, Table 1 lists the properties of a microcreped Celgard®laminated product Example 1, together with properties of the compositematerials used to produce the microcreped Celgard laminated product.Example 1 was processed through the Micrex® Corporation microcrepingprocess according to specification number C2000. FIG. 3 includes beforeand after photographs of one embodiment of the inventive CelgardZ-Series EZL2090 microcreped composite microporous membrane.

TABLE 1 Properties of Microcreped Celgard ® Z-Series EZL2090 CompositeMicroporous Membrane. EZL2090 (composite of Nonwoven EZ2090 membrane PP(PP and Microcreped Property Fabric membrane) nonwoven) EZL2090Thickness, um 130 20 83 263 Basis weight, g/m2 15 6 19 44 ASTM Gurley,<1 3 2 47 sec/10 cc Puncture Strength, 113 288 511 621 kg % Strain atLoad 5.1 3.7 3.9 5.6 PS test MD Stress at break, 47 903 267 88 kgf/cm²TD stress at break 27 609 159 74 % MD Elongation 50 106 89 193 at breakRecoverable MD none none very little All after 100% extension andrelease by hand

Example 1

Celgard® EZ2090 Z series polypropylene (PP) microporous membrane wasthermally laminated using a diamond diagonal surface pattern to anonwoven polypropylene (PP) fabric with a basis weight of 15 g/m². Theresulting product EZL2090 was microcreped using the Micrex® Corporationmicrocreping process according to specification number C2000 at atemperature of about 150 degrees F. and a pressure of about 40 psi.Microcreping of a 83 μm EZL2090 composite of a 130 μm nonwoven PP fabricto a 20 μm microporous Celgard® EZ2090 produced a 263 μm thickmicrocreped composite microporous membrane with a basis weight of 44g/m². This inventive microcreped composite membrane had an approximately20% increase in puncture strength and 100% increase in MD elongation atbreak when compared to the non-microcreped EZL2090. After a test sampleof the microcreped composite membrane was elongated to full extensionand released, recovery was nearly 100%. A low Gurley value of 47 sec/10cc is indicative of the high air permeability of the inventivemicrocreped composite membrane.

Example 2

Celgard® EZ3030 18 μm polypropylene (PP) microporous membrane wasthermally laminated using a dot surface pattern to a 106 μm nonwovenpolypropylene (PP) fabric with a basis weight of 11.7 g/m². MicrocrepedEZL3030 shown in FIG. 4 was prepared using the Micrex® Corporationmicrocreping process according to specification number C2000 at atemperature of about 150 degrees F. and a pressure of about 40 psi. Theinventive microcreped EZL3030 was 159 μm thick and had approximately a30% increase in puncture strength when compared to the puncture strengthof the composite layers. The zero Gurley value observed for themicrocreped EZL3090 is indicative of the very high air permeability. Inaddition, a 60% increase in the % Strain at load measured duringpuncture strength testing was observed indicating an increase inextensibility or stretch under load for the microcreped membrane.

TABLE 2 Properties of Microcreped Celgard ® EZL3030 CompositeMicroporous Membrane. Nonwoven PP EZ3030 Microcreped Property Fabric (PPmembrane) EZL3030 Thickness, um 106 17.7 159 Basis weight, g/m2 11.7 5.321.6 ASTM Gurley, sec/10 cc 2 1 0 Puncture Strength, kg 143 128 393 %Strain at Load PS 5.7 5.2 7.3 test MD Stress at break, 37.5 617.5 58.3kgf/cm² % Strain at Break 55.9 86.5 49.7

Test Methods

Gurley is measured by the ASTM D-726 method and is a gas permeabilitytest measured using the Gurley Densometer Model 4120 permeabilitytester. ASTM Gurley is the time in seconds required for 10 cc of air topass through one square inch of film at a constant pressure of 12.2inches of water.

Thickness is measured in micrometers, μm, using the Emveco Microgage210-A micrometer thickness tester and test procedure ASTM D374.

MD Tensile strength is measured using Instron Model 4201 according toASTM-882 procedure.

% MD elongation at break is the percentage of extension of a test samplemeasured at the maximum tensile strength needed to break a sample.

Puncture Strength is measured using Instron Model 4442 based on ASTMD3763. The measurements are made across the width of the microporousmembrane and the puncture strength defined as the force required topuncture the test sample.

Basis Weight the weight per unit sample area of a material and can beexpressed in grams/meter squared. It is the weight in grams of a testsample of known area in meters squared.

Films, especially thin films, are thought to be the most difficultmaterials to handle, microcrepe, compact, or the like. The thin porousmembranes or porous films of the present invention (for example, 5 to 50um thick microporous membranes) may be even harder to handle than solidfilms, but may better receive microcreping or compacting than solidfilms as the about 10% or more porosity, preferably about 30% or moreporosity, and more preferably about 50% or more porosity, may facilitatecreping. The thin composite or laminated porous membranes of the presentinvention (for example, 15 to 500 um thick composite microporousmembranes or laminates) may be easier to handle due to the non-woven orfabric layer.

In accordance with at least certain embodiments, this invention relatesto longitudinal treatment of thin porous materials, especially porousmaterials formed of a microporous membrane and a non-woven joinedthereto, for the purpose of microcreping, compacting, to soften, to makestretchy, etc.

In at least certain microcreping, the thin, flexible, elongate porousmaterial (length, web, sheet) is fed against a retarding means, isconfined against a drive surface and on the same side of the material asthe confining surface engaging it with a retarding surface, is subjectedto a continuous longitudinal compressive treatment of a running lengthof the flexible material by pressing it by means of a pressing assemblyinto driven engagement with a moving drive surface, the pressingassembly providing a confining surface and a retarding surface bothopposed to the drive surface and the retarding surface positioned beyondthe confining surface so that the material passes between the retardingand drive surfaces after it exits from beneath the confining surface,and wherein the pressing assembly comprises (1) a presser member and (2)coupling means for transmitting the force of the presser member to thematerial, and the coupling means comprises (1) confining means definingthe confining surface, (2) retarding means positioned at least in partbeyond the confining means and defining the retarding surface and (3)force transmitting means between the presser member and the confiningand retarding means, the presser member and coupling means are mountedfor movement relative to, each other longitudinally of the moving drivesurface, means are provided for effecting such relative movement whilesaid presser member is in pressing engagement with said coupling means,and the coupling means are so disposed and arranged with respect to thepresser member as, during such relative movement in one direction,progressively to force the retarding surface closer to the moving drivesurface from a relatively remote, ineffective position to positionscloser to such surface to increase progressively the retarding effect ofthe retarding surface on a material driven by the drive surface, and,during this same relative movement, to transmit sufficient force to theconfining surface to maintain material beneath it in non-slipping,driven engagement with the drive surface to the vicinity of thecommencement of the retarding surface, the flexible material is causedto travel with the drive surface without slippage to a point close tobut under the confining surface, in advance of the point where theretarding surface begins, between these points (generally less than aninch, and in the case of thin fabrics, less than ¼ inch), the materialis slippably confined to a restricted thickness, delivery by the drivesurface to the first point forces the material to immediately compressin its own plane against a confined column of compressed material priorto reaching the retarding surface, the retarding surface is inextensibleand after adjustment is fixed in the direction of travel of thematerial; on the other hand it is preferably resiliently yieldable inthe direction of thickness of the material, preferably the retardingsurface is comprised of a multiplicity of material gripping projectionshaving an aggregate retarding effect (e.g. hard grit grains bonded to anon-extensible backing sheet or projections of hard metal), and/or thelike.

The present invention is not limited to any particular lamination orcreping pattern, process, equipment, or the like. Micrex®/Microcrepers™creping equipment and a Plisse pattern may be preferred. As a very roughgeneralization of prior thinking—textiles will accept the widest rangeof creping patterns, followed by nonwovens, less so paper, andlastly—films. Microcrepes can be described in terms of their frequencyas well as amplitude, and can range from Very Fine, to Fine, to Medium,to Large, or the like. As a general rule in creping, it is easier toproduce a pattern which is coarse than one which is fine. One can alsouse two levels of crepe, or microcrepe in narrow bands to create aplisse effect. Plisse patterns can easily be modified on the machinewith little or no downtime or wasted material, for example, the newpattern device is cut with scissors from a piece of blue steel. Otherpatterns include a “skip” pattern, a “seersucker” pattern, a “doublecrepe” meaning both fine and coarse microcrepe, etc. In addition tomicrocreping, compacting, or creping, the thin flexible porous materialsof the present invention may be embossed, perforated, scored, flocked,scavengered, brushed, corduroyed, printed, gravure printed, rolled,ribbed, beat, surface raised, heat set, sueded, folded, roll folded,pleated, undulated, waved, and/or the like, on one or both surfaces,combinations thereof, on one or both surfaces, and/or the like.

At least selected embodiments, objects or aspects of the presentinvention are directed to novel, modified or treated microporousmembranes for use in textile related applications and which arepreferably composed of two or more dissimilar porous membrane ormaterial layers laminated together using heat, compression and/oradhesives. The preferred inventive laminated composite microporousmembrane is modified using a technique or treatment such as microcrepingto introduce permanent small, regularly spaced, crepes, profiles,compactions, pleats, or wrinkles into the laminated compositemicroporous membrane for the purpose of improving mechanical strength,elasticity and/or resiliency. In addition, the inventive modified,treated or microcreped microporous laminated membrane more preferablyhas significantly improved ‘hand’ or softness, has ‘next-to-the-skin’softness, and/or is quiet without crinkling noises during movement,which may be desired performance properties or characteristics of or intextile garments, materials or applications.

At least selected embodiments of the present invention are directed tonovel, improved, modified or treated microporous membranes for use intextile related applications and which are preferably composed of two ormore dissimilar porous membrane or material layers laminated togetherusing heat, compression and/or adhesives. The preferred inventivelaminated composite microporous membrane is preferably improved, treatedor modified using a technique or treatment such as microcreping tointroduce permanent small, regularly spaced, crepes, profiles,compactions, pleats, or wrinkles into the laminated compositemicroporous membrane for the purpose of improving mechanical strength,elasticity and/or resiliency. In addition, the inventive microcrepedmicroporous laminated membrane more preferably has significantlyimproved ‘hand’ or softness, has ‘next-to-the-skin’ softness, and/or isquiet without crinkling noises during movement, which may be desiredperformance properties or characteristics of or in textile garments,materials or applications.

At least certain embodiments, objects or aspects of the presentinvention are directed to microcreped or softened novel, improved,modified, or treated porous membranes, materials, composites, laminates,textiles, garments, textile materials, microporous membranes, materials,composites, laminates, textiles, garments, textile materials, compositemicroporous membranes which are composed of two or more dissimilarporous membrane or material layers laminated together, laminatedcomposite microporous membranes produced through the microcrepingprocess may offer a range of differentiated textile materials withwaterproof/breathable performance properties.

In accordance with at least selected embodiments, objects, or aspects,the present invention is directed to novel, improved, modified, ortreated porous membranes, materials, composites, laminates, textiles,garments, textile materials, and related methods. In accordance with atleast certain embodiments, the present invention is directed to novel,improved, modified, or treated microporous membranes for use in textilegarments, textile materials or related applications. In accordance withat least certain selected embodiments, the present invention is directedto novel, modified or treated composite microporous membranes which arecomposed of two or more dissimilar porous membrane or material layerslaminated together, for example, using heat, compression and/oradhesives. In accordance with at least particular selected embodiments,the laminated composite microporous membrane is modified using atechnique or treatment such as microcreping to introduce permanentsmall, regularly spaced, crepes, profiles, compactions, pleats, orwrinkles into the laminated composite microporous membrane for thepurpose of changing, modifying or improving certain characteristics orperformance such as mechanical strength, elasticity and resiliency. Inaddition, the inventive novel, improved, modified, treated, ormicrocreped microporous laminated membrane may have significantlyimproved ‘hand’ or softness which is a desired characteristic orperformance property in textile garments, materials or applications.

The present invention is directed to novel, improved, modified ortreated microporous membranes for use in textile related applicationsand which are preferably composed of two or more dissimilar porousmembrane or material layers laminated together using heat, compressionand/or adhesives. The preferred inventive laminated compositemicroporous membrane is modified using a technique or treatment such asmicrocreping to introduce permanent small, regularly spaced, crepes,profiles, compactions, pleats, or wrinkles into the laminated compositemicroporous membrane for the purpose of improving mechanical strength,elasticity and/or resiliency. In addition, the inventive microcrepedmicroporous laminated membrane more preferably has significantlyimproved ‘hand’ or softness, has ‘next-to-the-skin’ softness, and/or isquiet without crinkling noises during movement, which may be desiredperformance properties or characteristics of or in textile garments,materials or applications.

Many other modifications and variations of the present invention arepossible to the skilled practitioner in the field in light of theteachings herein. For example, although preferred to be porous ormicroporous, the membrane may be coated with a non-porous, porous ormicroporous coating or layer. It is therefore understood that, withinthe scope of the claims, the present invention can be practiced otherthan as herein specifically described.

We claim:
 1. A composite membrane comprising: a modified laminatedcomposite membrane composed of at least two dissimilar membranes, onemembrane having an average pore diameter in the range of 0.02-0.20microns, and the composite membrane having a recovery of between 20-100%after extension.
 2. The membrane of claim 1 wherein the membrane has atleast one of the following: waterproofness, breathability, greatlyenhanced usefulness and scope of application, increased mechanicalstrength to withstand the rigors of repeated use, a degree of stretchand recovery to enhance wearer comfort or to improve conformability totwists and bends, and improved hand or drape.
 3. The membrane of claim 1wherein the lamination is by heat, compression, and/or adhesive.
 4. Themembrane of claim 1 wherein the modification is regularly spaced crepes,profiles, compactions, pleats, or wrinkles.
 5. The membrane of claim 1wherein one membrane is a porous polymer membrane and another membraneis a nonwoven.
 6. The membrane of claim 1 wherein one membrane is aporous polymer membrane and another membrane is a different porouspolymer membrane.
 7. A composite microporous membrane comprising: acomposite microporous membrane modified, treated or microcreped using aprocess or treatment to introduce permanent small, regularly spaced,crepes, profiles, compactions, pleats, or wrinkles into the compositemicroporous membrane, the composite microporous membrane comprises amicroporous polymer membrane laminated to a woven or nonwoven porousmaterial, the laminated composite microporous membrane has small,regularly spaced, crepes, profiles, compactions, pleats, or wrinkles,wherein the modified, treated or microcreped composite microporousmembrane preferably has improved puncture strength, increased % MDelongation at break, improved level of stretch and recovery, isresilient, and/or has a soft ‘hand’ or drape.
 8. The compositemicroporous membrane of claim 7 wherein the average diameter of thepores in the microporous polymer membrane is in the range 0.02 to 0.20μm.
 9. The composite microporous membrane of claim 7 wherein one or morelayers of a nonwoven fabric has been thermally, ultrasonically or withthe use of adhesives laminated to the microporous polymer membrane priorto modification, treatment or microcreping.
 10. The compositemicroporous membrane of claim 7 wherein machine direction stretch can beup to 200%.
 11. The composite microporous membrane of claim 7 whereinthe recovery of the membrane is between 20 to 100% after extension. 12.The composite microporous membrane of claim 7 wherein the polymermembrane is water impervious.
 13. The composite microporous membrane ofclaim 12 wherein the polymer membrane is vapor permeable.
 14. A modifiedmicroporous membrane comprising: a microporous membrane modified using aprocess or treatment to introduce permanent small, regularly spaced,crepes, profiles, compactions, pleats, or wrinkles into the microporousmembrane to form a modified microporous membrane, and wherein themodified microporous membrane has improved puncture strength, increased% MD elongation at break, improved level of stretch and recovery, isresilient, and/or has a soft ‘hand’ or drape.
 15. The microporousmembrane of claim 14 wherein the modified microporous membrane hasimproved puncture strength, increased % MD elongation at break, improvedlevel of stretch and recovery, improved resiliency, and has a soft‘hand’ or drape as compared to non-modified microporous membranes. 16.In a textile or garment, the improvement comprising the microporousmembrane of claim
 14. 17. A method of forming a modified microporousmembrane comprising: introducing via a process or treatment permanentsmall, regularly spaced, crepes, profiles, compactions, pleats, orwrinkles into a microporous membrane to form a modified microporousmembrane, the modified microporous membrane having improved puncturestrength, increased % MD elongation at break, improved level of stretchand recovery, resiliency, and/or has a soft ‘hand’ or drape.
 18. Themethod of claim 17 wherein the microporous membrane has multiple layers.19. The method of claim 18 wherein one layer is a non-woven layer ormaterial.
 20. The method of claim 18 wherein one layer is a coating.